1 files changed, 41 insertions, 0 deletions
diff --git a/web_src/js/bootstrap.js b/web_src/js/bootstrap.js
new file mode 100644
index 0000000000..cf13b2a559
--- /dev/null
+++ b/web_src/js/bootstrap.js
@@ -0,0 +1,41 @@
+import {joinPaths} from './utils.js';
+
+// DO NOT IMPORT window.config HERE!
+// to make sure the error handler always works, we should never import `window.config`, because some user's custom template breaks it.
+
+// This sets up the URL prefix used in webpack's chunk loading.
+// This file must be imported before any lazy-loading is being attempted.
+__webpack_public_path__ = joinPaths(window?.config?.assetUrlPrefix ?? '/', '/');
+
+export function showGlobalErrorMessage(msg) {
+  const pageContent = document.querySelector('.page-content');
+  if (!pageContent) return;
+  const el = document.createElement('div');
+  el.innerHTML = `<div class="ui container negative message center aligned js-global-error" style="white-space: pre-line;"></div>`;
+  el.childNodes[0].textContent = msg;
+  pageContent.prepend(el.childNodes[0]);
+}
+
+/**
+ * @param {ErrorEvent} e
+ */
+function processWindowErrorEvent(e) {
+  showGlobalErrorMessage(`JavaScript error: ${e.message} (${e.filename} @ ${e.lineno}:${e.colno}). Open browser console to see more details.`);
+}
+
+function initGlobalErrorHandler() {
+  if (!window.config) {
+    showGlobalErrorMessage(`Gitea JavaScript code couldn't run correctly, please check your custom templates`);
+  }
+
+  // we added an event handler for window error at the very beginning of <script> of page head
+  // the handler calls `_globalHandlerErrors.push` (array method) to record all errors occur before this init
+  // then in this init, we can collect all error events and show them
+  for (const e of window._globalHandlerErrors || []) {
+    processWindowErrorEvent(e);
+  }
+  // then, change _globalHandlerErrors to an object with push method, to process further error events directly
+  window._globalHandlerErrors = {'push': (e) => processWindowErrorEvent(e)};
+}
+
+initGlobalErrorHandler();